#include <iostream>
#include <vector>
#include <map>
#include <algorithm>
using namespace std;

#define REP(i, S, E) for(int i=(S); i<=(E); i++)

int N, K;
int dp[5009][5009][2];
vector<pair<int, int>> pizza;

int main(void){
    
    cin >> N >> K;
    pizza.resize(N+1, {-1, -1});
    
    REP(i, 1, N){
        int p, d;
        cin >> p >> d;
        pizza[i] = make_pair(p, d);
    }
    
    sort(pizza.begin(), pizza.end());
    
    REP(i, 1, N){
        REP(j, 0, K){
            int p = pizza[i].first;
            int d = pizza[i].second;
            
            dp[i][j][0] = max(dp[i][j][0], dp[i-1][j][0]);
            dp[i][j][0] = max(dp[i][j][0], dp[i-1][j][1] + d);
            
            if (p > j){
                dp[i][j][1] = max(dp[i][j][1], dp[i-1][j][1]);
            }else{
                dp[i][j][1] = max(dp[i][j][1], dp[i-1][j][1]);
                dp[i][j][1] = max(dp[i][j][1], dp[i-1][j-p][0] + d);
            }
        }
    }
    
    cout << dp[N][K][1] << endl;
    
    return 0;
    
}